2. fall asleep fast, as when one is extremely tired; - Example: "after the long drive, we zonked out and slept for 10 hours"
WordNet (r) 3.0 (2006):
zonk out
v 1: lose consciousness due to a sudden trauma, for example
[syn: zonk out, pass out, black out]
2: fall asleep fast, as when one is extremely tired; "after the
long drive, we zonked out and slept for 10 hours"